At present, cell cultures of various animals and plants are performed, and also new cell culture methods are in development. The technologies of the cell culture are utilized, such as to elucidate the biochemical phenomena and natures of cells and to produce useful substances. Furthermore, with cultured cells, an attempt to investigate the physiological activity and toxicity of artificially synthesized medicals is under way.
Some cells, particularly a lot of animal cells have the adhesion dependency of adhering to some materials and growing thereon, and cannot survive for a long period under a flotation condition out of organisms. For culturing cells having such adhesion dependency, a carrier to which cells can adhere is necessary, and in general, a plastic culture dish with uniformly applied cell adhesive proteins such as collagen, fibronectin and the like is used. It is known that these cell adhesive proteins act on cultured cells, make the cells adhere easily, and exert an influence on the form of cells.
On the other hand, there is a technology reported of adhering cultured cells only onto a small part on a base material and arranging them. By such a technology, it is made possible to apply cultured cells to artificial organs, biosensors, bioreactors and the like. As the method for arranging cultured cells, there is a method adopted in which a base material having a surface that forms a pattern different in easiness of adhesion to cells is used, cells are cultured on the surface of this base material and allowed to adhere only onto surfaces processed so that cells adhere, and thereby the cells are arranged.
For example, in the patent document 1, an electric charge-retaining medium on which an electrostatic pattern is formed is applied to culture cells for the purpose of proliferating nerve cells in a form of circuit, and the like. Furthermore, the patent document 2 tries to arrange cultured cells on a surface on which a cell adhesion-inhibiting or cell adhesive photosensitive hydrophilic polymer has been patterned by a photolithography method.
Furthermore, the patent document 3 discloses a cell culture base material on which a substance such as collagen affecting on the adhesion ratio and form of cells is patterned, and a method for producing this base material by a photolithography method. By culturing cells on such a base material, a larger amount of cells can be adhered on a surface on which collagen or the like is patterned, to realize patterning of cells.
However, depending on its application, there is the case where such patterning of a cell culture portion is required to be a finely processed patterning. When carrying out patterning by photolithography using a photosensitive material as mentioned above, a fine pattern can be obtained. However, the cell adhesive material must have photosensitivity and there is therefore the problem that the range of the choice of a cell adhesive material is much narrowed because it is difficult to chemically modify such as biogenic polymers to impart such photosensitivity to these polymers. Also, in a photographic method using a photoresist, it is necessary to use a developer and the like, which sometimes have an adverse influence on cell culture.
Moreover, a microcontact printing method is proposed from George M. Whitesides at Harvard University as a method of forming a fine pattern of a cell adhesive material (for example, Patent Document 4, Patent Document 5, Patent Document 6 and Patent Document 7). However, this method has the problem that it is difficult to industrially produce a cell culture substrate having a pattern of a cell adhesive material by using this method.
If the functional differentiation of cells and the functionalization of a cell aggregate by laminate coculturing with heterocells can be attained while retaining a cell pattern, this is of deep significance in the fields of cell tissue technologies. However, it is generally difficult to retain a cell pattern while culturing cells for a long time. This is because the protein secreted from culture cells is adsorbed gradually with time to the surface of a cell adhesion inhibiting portion, whereby the surface of the cell adhesion inhibiting portion resultantly has cell adhesive property.    Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2-245181    Patent Document 2: JP-A No. 3-7576    Patent Document 3: JP-A No. 5-176753    Patent Document 4: U.S. Pat. No. 5,512,131    Patent Document 5: U.S. Pat. No. 5,900,160    Patent Document 6: JP-A No. 9-240125    Patent Document 7: JP-A No. 10-12545